code: def test_skybox_example():
      texture = examples.load_globe_texture()
      texture.cube_map = False
      assert texture.cube_map is False
  
      texture.cube_map = True
      assert texture.cube_map is True
  
      skybox = texture.to_skybox()
      assert isinstance(skybox, vtk.vtkOpenGLSkybox)
  
imports: import numpy
  import pytest
  import vtk
  import pyvista
  from pyvista import examples
  from pyvista.core.errors import VTKVersionError
  from pyvista.plotting.texture import numpy_to_texture
label_desc: Use image node_id 8 for calling a global function with example usage: test_skybox_example() without return types